AMSTERDAM, Sept 12 (Reuters) - Nearly a third of all buildings on the Dutch-ruled part of the Caribbean island of Saint Martin were destroyed and more than 90 percent damaged by Hurricane Irma, the Dutch Red Cross said on Tuesday.

The aid agency had surveyed 5,500 structures before the storm and made the assessment based on photographs provided by the Defence Ministry in the Netherlands.

Irma killed four people and injured dozens on the Dutch side of the island. The remainder of the island is administered by France. (Reporting by Anthony Deutsch; Editing by Kevin Liffey)